Cyclic ortho ester fuel additive

Abstract

The invention relates to liquid hydrocarbons containing cyclic ortho esters as dehydrating dehydrating icing inhibitors and to methods of using the compounds. The liquid hydrocarbons include fuels such aviation fuels, lubricants, hydraulic fluids and hydrocarbon solvents.

Description

BACKGROUND OF THE INVENTION[0001]The invention relates to liquid hydrocarbons such as hydrocarbon fuels, hydraulic fluids, lubricants or solvents, comprising cyclic ortho ester dehydrating icing inhibitors. The hydrocarbon fuels include aviation fuels. Methods of inhibiting ice crystal formation and ice inhibiting compounds are also provided.[0002]Solubility of water in the current context refers to the maximum water concentration which can dissolve in any given amount of hydrocarbons at a specific temperature and air humidity; this is strongly dependent upon the chemical composition of the fuel itself [1, 2].[0003]Dissolved water is often a normal component of liquid hydrocarbons and is vaporised on combustion of hydrocarbon fuels. However, free water can freeze and block fuel or other feed lines. The water can also support microbial growth and contribute to corrosion. There is therefore a need to remove water or reduce the amount of ice crystal formation in liquid hydrocarbons.[00...

AI Technical Summary

Benefits of technology

The patent describes a method to remove water from liquid hydrocarbons using cyclic ortho esters. These esters are effective without the need for additional acid catalysts, which can corrode fuel tanks and pipes. The esters create reaction products that help reduce the freezing point of water and are toxicologically safe. The structure of the esters also makes it easy to modify their reactivity with water, which means they can be used in hydrocarbons without needing acid present. These esters can produce alcohols and esters that function as anti-freeze agents and have anti-microbial properties. The patent also discusses the role of specific chemicals in affecting the solubility of the reaction products.Adding methyl groups to certain parts of the molecule can increase the reactivity of the cyclic ortho ester with water, which means less acid is needed in the fuel. Overall, this method can improve the quality and efficiency of fuel production without adding any harmful chemicals.

Problems solved by technology

However, free water can freeze and block fuel or other feed lines.

However, even if jet fuel enters the fuel tank without free water, this does not prevent its formation.

Free water can starve engines, support microbial growth, contribute towards corrosion and furthermore freeze, risking plugging filters in the aircraft.

The industry has developed equipment and procedures to mitigate these problems, but challenges remain [1, 3].

The aviation industry has identified several problems related to the interaction of FSII and “wet” fuel, which can actually undermine fuel protection.In addition to being hydrophilic, di-EGME is also hygroscopic—this additional characteristic leads to an uptake of atmospheric water during blending operations which affects its solubility in fuel.Di-EGME has a very high water-fuel partitioning ratio: it preferentially dissolves in water.

Unless replenished, the jet-fuel is essentially “stripped” of its protection against icing.The presence of di-EGME in the water contained within the fuel alters interfacial properties, and can impair the performance of filters and monitors.

Particularly, the separation efficiency of filter / coalescers can be compromised [8].

In addition, FSII are toxic at the concentrations required for effective de-icing.

‘Water bottoms’ drained from storage tanks, fuel system sumps and filters inevitably contain higher concentration of di-EGME, creating concerns about the handling and disposal of these wastes [10].

FSII are only mildly irritating, but they are rapidly absorbed by the skin.

Vapours can cause irritation to the eyes and the respiratory system.

Di-EGME is biodegradable in wastewater treatment system; however concentrations found in water bottoms could be high enough to disrupt the microbiological process.

In the environment, the high oxygen demand required for decomposition results in less available oxygen for aquatic organisms [12].

Liquid hydrocarbons, such as aviation fuels present a number of problems for the selection of water scavenging compounds to be used as dehydrating icing inhibitors.

Such low temperatures can dramatically reduce the kinetic energy of participating molecules, to the point that a chemical reaction slows down or effectively stops.

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